Elaborated the notes on the XML support.
Elaborated the notes on the XML support.

In the limits.h comment, noted that INT_MAX and LONG_MAX are guaranteed
to be defined.

Noted that Reliant UNIX now gets proper API support for extension modules.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator